Vitamin D

Of all the vitamins, it seems like vitamin D has had the most air time of late. Certainly in our clinics, it’s the one patients seem to ask most about – are they getting enough, how do they know if they are getting enough and do they need to take supplements?

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Vitamin D helps our bodies to regulate the crucial minerals Calcium and Phosphate in our bodies. We need these to keep our bones, teeth, nerves and muscles healthy.

A lack of vitamin D causes bone abnormalities – you might have heard of rickets? Rickets is a disease in children caused by a vitamin D deficiency.

For most of us, we actually get our vitamin D from exposure to sunlight. This means here in the UK, it can be a challenge to get enough sun during the long winter months. We all know the dangers of sun exposure and it’s a sad fact that skin cancers seem to be on the rise. There is a real delicate balance between enabling the sun to provide us with enough vitamin D and over-exposing our skin to the sun and increasing our risk of sun-related skin damage.

It is recommended that to allow enough exposure of the skin to the sun, that our forearms, hands or lower legs are uncovered, for short periods of time, without sunscreen. There is no set amount of time we need in the sun – and this is because we all make vitamin D at different rates. Darker skin colours seem to take longer to produce vitamin D and will need longer in the sun than those with lighter skin colours.

Being in the sun enough to cause the skin to burn is never recommended – and if you do start to feel burnt – you need to cover up or apply a good strength sunscreen (at least SPF 15). Increased time in the sun or allowing the skin to burn can increase the risk of developing sun-related skin damage or skin cancers.

There are some foods which can provide vitamin D such as red meat, liver, fortified foods, cereals and oily fish such as salmon or mackerel. However if you follow a diet that does not include meat – it can be especially challenging to make sure you get enough vitamin D.

Children over the age of one and adults need 10 micrograms of vitamin D a day.

Recently, the guidelines on vitamin D supplementation changed. Here in the UK it is recommended that babies from birth to the age of one are given a daily supplement containing up to 10 micrograms of vitamin D. However if your baby is fed by formula, most of these have vitamin D and as such they would not need supplementation until they were having less than a pint (around 500ml) of formula feed. Children up to the age of four should also be given a daily supplement.
There is now advice that adults should also have a supplement during winter months, when we are less able to get our fix of sunshine.

It is also worth considering those who are at higher risk of vitamin D deficiency – and primarily these are people who do not get much sun exposure. Whether that be due to immobility or being housebound, or those who choose to cover up most of their body with clothing.

 

 

 

You can get too much vitamin D – and this can cause an increased build up of calcium. Although we need calcium to keep our bones strong, actually too much can weaken our bones and cause heart and kidney problems.

Vitamin B

Next in our quick series of Vitamin FAQ’s we look at vitamin B (if you missed Vitamin A – you can read it here).

There are actually lots of different types of vitamin B, but for our bodies the main ones are:

  • B1 – thiamin
  • B2 – riboflavin
  • B3 – niacin
  • B5 – pantothenic acid
  • B6 – pyridoxine
  • B7 – biotin
  • Folate (folic acid)
  • B12

 

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In general, they all aid the process of breaking down key aspects of our food, releasing much needed energy into our system, as well as helping keep our eyes, skin and nervous system healthy.

Vitamin B6 has a specific role in using and storing the protein and carbohydrates we take in as part of our diet and helping our body to produce haemoglobin. Haemoglobin is what makes our blood look red and critically carries oxygen around the body.

Folic acid – most well known as the supplement that is needed in pregnancy – is crucial for reducing the risk of developmental defects of the central neural tube of unborn babies. The neural tube is the early form of our central nervous system. Developmental problems at this crucial stage of a baby’s growth can lead to problems such as spina bifida. However it’s not just pregnant women – it also helps all of us to make healthy red blood cells.

Perhaps the most well known is vitamin B12. This actually helps us to use folic acid. It also is vital in keeping the nervous system healthy and plays a key role in making red blood cells.

With so many types of B vitamins, the ways we can get this into our diet are varied. Importantly, some of these vitamins cannot be stored in the body – so we need a daily supply in our diet. Thiamin cannot be stored – and it’s recommended that men need around 1mg/day and women around 0.8mg/day. Similarly we need daily riboflavin at around 1.3mg for men and 1.1mg for women. Niacin also cannot be stored and men should aim for around 16.5mg and women around 13mg.

A word of caution about niacin – too much for a long time can lead to liver problems and cause skin flushes. Similarly B6 in excessive amounts  (e.g. more than 200mg) can lead to a problem called peripheral neuropathy. This is a problem of the nervous system where we can develop loss of sensation in our limbs (peripheries). Men should aim for around 1.4mg/day of B6 and women around 1.2mg.

Many foods are rich in a number of B vitamins including: eggs, fresh/dried fruit,  leafy green vegetables, broccoli, wholegrain bread, fortified cereals, milk (cow’s), nuts,

Some specific diets e.g. vegetarians and vegans can sometimes struggle with B vitamins, and B12 in particular. B vitamins are in abundance in animal products – meats, fish, eggs, cows milk etc. However with careful planning, it is possible to get all the recommended amounts in your diet without additional supplementation. However, a multivitamin can be a helpful addition to more restrictive diets and might be worth discussing with your doctor.

Folic Acid

As we have already learned, folic acid (or folate) is pivotal in a baby’s development and throughout our life by helping us produce red blood cells. The average adult needs 200micrograms of folic acid/day and it cannot be stored meaning you need a daily amount. An additional supplement is provided to pregnant women – either 400mcg of 5mg depending on their medical history. Caution is required with additional supplementation – too much can possibly cover up an existing B12 deficiency.

This is found in vegetables such as asparagus, peas, sprouts and broccoli. It is also prevalent in liver but this should be avoided in pregnancy.

B12

The most well known of all B vitamins is B12. A deficiency of B12 is something that has been in the media more of late. This is the vitamin that those who avoid animal products in their most struggle with – as it is only found naturally in animal products – meats, milks, eggs.  It is some fortified cereals however.

We need around 1.5micrograms/day and this is something we can store in the body.

Deficiency in B12 causes wide ranging symptoms including low mood, changes in mental state, altered or abnormal sensation, fatigue, irritability, anaemia and reduced fertility. Whilst some changes can be reversed with treatment, if left unchecked and untreated, some of the damage can be permanent.